Welcome to SR. I'm sorry for the pain that brings you here. You sound like me with the moods. Up, down, life of the party, the lowest of lows. Quitting was the only solution for me.
There is an AA saying that holds true even if you never go to AA. It works if you work it. Make a plan, and work that plan. Hope only got me so far. I had to take serious action. Coming here for support is a good start for you. I'm glad you did.